A circle follows the mouse cursor across an SVG canvas, updating its position in real time to mirror the pointer's movement. The example demonstrates React's state management and event handling, using the `useState` hook to track mouse coordinates and an `onMouseMove` event listener on the SVG element. ReactDOM renders the component, which draws a navy circle with a radius of 30 pixels against a blank white background. The visualization highlights a simple interactive pattern with minimal code, relying solely on React's declarative rendering rather than any additional libraries.